Does the placebo effect cure?

[Mulder]

It is well known that the placebo effect can make people FEEL better but can it actually cure them?

I can see how it might cure a psychosomatic condition but what about a physical systemic disease? Anyone know of any cases where it has cured anything apart from psychological conditions?

[Matt]

It is well known that the placebo effect can make people FEEL better but can it actually cure them?

I can see how it might cure a psychosomatic condition but what about a physical systemic disease? Anyone know of any cases where it has cured anything apart from psychological conditions?

As I understand it the placebo effect can reduce swelling/inflamation. I'd look for a citation but you can operate Pub Med/Google schoolar as well as I can.

In some cases I might imagine swelling and inflamation may compound problems and delay recovery. As such the placebo effect could have real positive effects.

[Tony Williams]

I recall reading somewhere (sorry, can't place the source) that the placebo effect is only temporary. Once it wears off, you're back where you were.

[Matt]

I recall reading somewhere (sorry, can't place the source) that the placebo effect is only temporary. Once it wears off, you're back where you were.

Well of course for self limiting conditions it's more where you would have been anyway (perhaps all better) rather than where you were.

Having said that the placebo effect could potentially have long lasting knock on effects not least if it affects the patients actions during the time the placebo effect is active.

Lets say the only remedy science can offer is a bit of fresh air and exercise, but nonetheless there good clinical evidence that this is an effective treatment. Now lets say that two groups are treated one by a cheerful positive doctor who takes pains to convince patients they should expect imediate effects and one by a down at heel practictioner who appologises for not being able to offer anything better and is rather pesamistic about it's effects. In other words in one group the treatment is coupled with a strong placebo effect and in another group only a weak placebo effect.

It would hardly be suprising that in the days that immediatly followed this advice the group with the benfit of the strong placebo effect will feel better than the other group. Not only that but you'd expect this feelign of wellbeing to carry over not only to their comitment to the exercise regime but their range of movement and activity in day to day life.

[Tony Williams]

Well of course for self limiting conditions it's more where you would have been anyway (perhaps all better) rather than where you were.
True enough - the body recovers from most ailments if left to its own devices. I suppose that if a placebo makes sufferers feel better while this process is going on, then it's all to the good.


Having said that the placebo effect could potentially have long lasting knock on effects not least if it affects the patients actions during the time the placebo effect is active.

Lets say the only remedy science can offer is a bit of fresh air and exercise, but nonetheless there good clinical evidence that this is an effective treatment. Now lets say that two groups are treated one by a cheerful positive doctor who takes pains to convince patients they should expect imediate effects and one by a down at heel practictioner who appologises for not being able to offer anything better and is rather pesamistic about it's effects. In other words in one group the treatment is coupled with a strong placebo effect and in another group only a weak placebo effect.

It would hardly be suprising that in the days that immediatly followed this advice the group with the benfit of the strong placebo effect will feel better than the other group. Not only that but you'd expect this feelign of wellbeing to carry over not only to their comitment to the exercise regime but their range of movement and activity in day to day life.
That isn't quite what I would describe as a typical placebo effect. After all, anybody lacking in fresh air and exercise who is persuaded (enthusiastically or otherwise) to take some will probably feel better as a result, because there is genuine benefit from it. This is different from the situation in which someone feels better despite being given a "treatment" which is of no real benefit at all.

[Pebble]

Examples that spring to mind include the orginal sham operation for intractible coronary disease. One group had their chest split and the mammary artery buried in the heart, the second just had a scar. The exercise performance increased by the samer amount in both, with 40% relieved of their angina. In severe heart failure trials, 60% have substantial improvement with placebo for up to 18 months (but die at the same rate). More recently in patients with severe migraine, sham procedures (to close patent foramen ovale) improved the frequency and severity of migraines as the 'real' procedure.

While one can claim that any of these conditions have a 'psychsomatic' component these individuals all had clear pathology, and improved wellbeing and functional capacity after placebo therapy.

The other way of looking at this is the Indian Atheist Group, who learn to control their reaction to tissue penetration. Thus can put hooks through their skin and suspend themselves from these hooks, or place metal spikes through their cheeks, to demonstrate that the brains reaction to stimuli is a pivotal component of the bodies reaction.

[Tony Williams]

The issue of mental control over physical symptons is an interesting one. Certainly people can banish pain (there was a woman on TV just the other week who had surgery without anaesthetic - she hypnotised herself). Conversely, I read not long ago that having a positive, "fighting" attitude to combating potentially lethal ailments has no effect at all on the death rate, contrary to popular belief.

[JJM]

https://content.nejm.org/cgi/content/full/344/21/1594 (https://content.nejm.org/cgi/content/full/344/21/1594)

Conclusions We found little evidence in general that placebos had powerful clinical effects. Although placebos had no significant effects on objective or binary outcomes, they had possible small benefits in studies with continuous subjective outcomes and for the treatment of pain. Outside the setting of clinical trials, there is no justification for the use of placebos.I heard an instructive anecdote. The guy had tinnitus for several weeks, and went to a specialist. the doctor did some tests and suggested that the guy wait a little longer to see if it would resolve itself. The guy asked what could be causing it, the doctor nonchalantly suggested a brain tumor.

The guy was rattled by that suggestion; but he went home. On the trip home, he realized that the noise was gone and, years later, he said it had never recurred. I guess you could say he was cured; but with no treatment of any sort.


The issue of mental control over physical symptons is an interesting one. Certainly people can banish pain (there was a woman on TV just the other week who had surgery without anaesthetic - she hypnotised herself). {snip}It is common for such "operations" to be faked, ala psychic surgery. Also, some demonstrations use people who are so drugged that they cannot feel, or complain, much.

[Tony Williams]

It is common for such "operations" to be faked, ala psychic surgery. Also, some demonstrations use people who are so drugged that they cannot feel, or complain, much.
It was a serious news item and the operation was carried out in an NHS hospital. There's a report on the BBC news website here (http://news.bbc.co.uk/2/hi/health/7494283.stm)

I also found this (http://news.bbc.co.uk/2/hi/uk_news/england/sussex/7355523.stm)

[Pebble]

It was a serious news item and the operation was carried out in an NHS hospital. There's a report on the BBC news website here (http://news.bbc.co.uk/2/hi/health/7494283.stm)

I also found this (http://news.bbc.co.uk/2/hi/uk_news/england/sussex/7355523.stm)


The BBC alright, lets rewrite all textbooks. After all who could fool a journalist?

Not saying it can't be done, but your evidence base is thin

[JJM]

It was a serious news item and the operation was carried out in an NHS hospital. There's a report on the BBC news website here (http://news.bbc.co.uk/2/hi/health/7494283.stm)

I also found this (http://news.bbc.co.uk/2/hi/uk_news/england/sussex/7355523.stm)I am not impressed. There have been news reports of psychic surgeons, too. You can read about it in "Flim Flam" (Prometheus, 1982) by James Randi. You can also see a humorous, staged example in his video documentary "The Secrets of the Psychics" (Nova, WBGH, 1993). The video is inexpensive, available through http://www.randi.org/ Also see "Pain" by Patrick Wall (Columbia U. Press, 2000) in which he discusses the situation with respect to acupuncture and hypnosis.

Certainly, there are people with a high threshold for pain. Certainly, if one combines that with the ability to become famous and make a lot of money, you could grit your teeth and bear it for a while.

Reporters are not known for letting the facts get in the way of a good story.

[Matt]

It was a serious news item and the operation was carried out in an NHS hospital. There's a report on the BBC news website here (http://news.bbc.co.uk/2/hi/health/7494283.stm)

I also found this (http://news.bbc.co.uk/2/hi/uk_news/england/sussex/7355523.stm)

We're (http://www.skeptics.org.uk/forum/showthread.php?t=2731) Aware (http://www.skeptics.org.uk/forum/showthread.php?t=2408)

[Tony Williams]

We're (http://www.skeptics.org.uk/forum/showthread.php?t=2731) Aware (http://www.skeptics.org.uk/forum/showthread.php?t=2408)
OK, thanks.

[Mike Hall]

I'm not convinced the Placebo Effect even exists in any physiological sense, and I don't see any biological plausibility in the hypothesis that actively doing nothing is somehow better than passively doing nothing.

Measured against an objective standard, the effect consistently fails to manifest. It is only when measured against some subjective criterion - such as pain relief - that placebos are seen to have an effect. Which suggests that placebo action is perceptual not biological.

You perceive less pain because you think you perceive less pain. But the placebo hasn't, and couldn't, alter the rate at which your pain receptors fire. The best it can do is let you persuade yourself to ignore them.

[Tony Williams]

You perceive less pain because you think you perceive less pain. But the placebo hasn't, and couldn't, alter the rate at which your pain receptors fire. The best it can do is let you persuade yourself to ignore them.
Which takes us back to self-hypnosis ;)

I was amused by an article in New Scientist a few months back which said that in one clinical trial, those on the placebo reported better results than those on the medicine being tested.

It makes one wonder how much of the perceived benefit from medicines is real and how much psychological. Particularly since recent research has shown that there is a big genetic component in how people respond to certain medicines; they work well with some people, not at all with others.

And other research has shown that patients kept in light, airy and pleasantly-decorated wards do better than those in less attractive environments.

How people are treated also seems to make a difference. I suspect that a lot of the benefit reported by people using alterative therapies (the more established ones rather than the obvious scams) comes from the fact that they often involve a long consultation with a sympathetic practioner rather than the production-line speed of passing through a doctor's surgery.

All of which tends to indicate that mental states can make a difference, however they are induced. Obviously it's not likely to help with serious physical ailments, but a lot of reported ailments these days have no measurable symptoms, just what the patients report.

[Matt]

I'm not convinced the Placebo Effect even exists in any physiological sense, and I don't see any biological plausibility in the hypothesis that actively doing nothing is somehow better than passively doing nothing.

Measured against an objective standard, the effect consistently fails to manifest. It is only when measured against some subjective criterion - such as pain relief - that placebos are seen to have an effect. Which suggests that placebo action is perceptual not biological.

You perceive less pain because you think you perceive less pain. But the placebo hasn't, and couldn't, alter the rate at which your pain receptors fire. The best it can do is let you persuade yourself to ignore them.

It's actually quite fascinating how the placebo effect works. Firsly I don't claim to know how it works nor do I claim that anybody has doen much more than scratvch the surface. however it is an undoubtable empirical fact that there is a physiological (neurobiological) effect. Most tellingly an olpiod agonist (something that stops opiate pain killers from working) may also block the placebo effect.

http://www.jneurosci.org/cgi/content/full/25/45/10390

[Mike Hall]

It's an interesting study, but I remain unconvinced. It's hardly surprising that administering substances which effect brain chemistry would also alter your perception.

I'll read the full article when I get the time :smiley:

[Pebble]

I'm not convinced the Placebo Effect even exists in any physiological sense, and I don't see any biological plausibility in the hypothesis that actively doing nothing is somehow better than passively doing nothing.





Placebo controlled trials show that there is a consistent placebo effect. This is certainly largest where there is subjective measures of outcome. The problem is where does subjective begin and end. Exercise performance in angina and time to ECG changes with exercise are affected by placebo, so is freuqency of hospital admissions in heart failure, improvement of peak flow in asthma etc.

Given the innervation of the human body, to suggest that state of mind does not influence vital processes is clearly wrong (heart rate, blood pressure, degree of sweating can all be controlled to a degree by mental processes alone) - so this may explain the apparent influence of placebo over so called physiological processes, but that is unproven

[Matt]

It's an interesting study, but I remain unconvinced. It's hardly surprising that administering substances which effect brain chemistry would also alter your perception.

I'll read the full article when I get the time :smiley:

Surely it should be hardly suprising that someone's mental state being affected by a placebo should also effect brain chemistry. Many non pharmacological stimuli effect brain chemistry, why should the placebo effect be any different.

[Mike Hall]

Indeed - which is exactly my point. Placebo doesn't do anything to treat the actual problem - it merely alters your perception of the problem.

Things get more complicated, of course, when you consider that some people are mind/body dualists and others are monists. Myself, I'm a monist; I don't think there is a distinction between mind and brain. Any change in perception has an associated physical change. And in this respect, if placebo has a perceptual effect, then there is an associated causal physiological change.

But this physiological change has no bearing on your problem - as is seen consistently when placebo is tested against objective outcomes. Doesn't matter what placebo you feed a patient - it's not going to heal their broken leg or send their cancer into remission.

Important Question (and one for which I do not have an answer):

If a patient reports they feel better, even when all clinical data suggests no improvement, are they better?

[SimonC]

Important Question (and one for which I do not have an answer):

If a patient reports they feel better, even when all clinical data suggests no improvement, are they better?

I would think that, in a patient with a self-limiting condition, the answer would be 'yes' - the patient may experience diminished symptoms while the illness subsides - that seems to be the ideal scenario. My caveat to this would be that the patient might feel more inclined to socialise/work/etc while the condition is still contagious, thus increasing the possibility of passing it to others.

In the case of a terminal illness the patient might convince him/herself that they 'feel better' but, presumably, only until the symptoms become overwhelming. At best I would see this as a deferment of suffering. And I'm not convinced that the inevitable suffering would not be worse because of the initial false-hope.

[Mike Hall]

But is the "experience" of diminished symptoms the same as diminished symptoms? I'm not sure it is.

Consider pain, for example. You experience pain because some localised trauma occurs in your body, this causes a reaction in the pain receptors which send nerve impulses up your spinal cord where they are interpreted by your brain as pain.

A placebo may change your interpretation of the signal, but it doesn't change the pain signal itself. It does not change the original trauma, it does not change the reaction of your pain receptors, it does not change the impulses going up your spine. It can't - it's inert. By any objective measure, your condition is unchanged. But the patient reports an improvement.

Is there an improvement? I don't know. The pain stays the same, it is the emotional response that is altered.

By way of analogy - did anyone see that episode of Bullshit! where Penn and Teller were selling people expensive bottled water in a restaurant? The patrons of the restaurant reported they were able to taste the difference between various brands of bottled water when actually they were all being filled in the yard behind the restaurant by a bloke with a hosepipe.

Did the water taste different? I don't know. The water stays the same, it is the emotional response that is altered.

[Matt]

But is the "experience" of diminished symptoms the same as diminished symptoms? I'm not sure it is.

Consider pain, for example. You experience pain because some localised trauma occurs in your body, this causes a reaction in the pain receptors which send nerve impulses up your spinal cord where they are interpreted by your brain as pain.

A placebo may change your interpretation of the signal, but it doesn't change the pain signal itself. It does not change the original trauma, it does not change the reaction of your pain receptors, it does not change the impulses going up your spine. It can't - it's inert. By any objective measure, your condition is unchanged. But the patient reports an improvement.

Is there an improvement? I don't know. The pain stays the same, it is the emotional response that is altered.

By way of analogy - did anyone see that episode of Bullshit! where Penn and Teller were selling people expensive bottled water in a restaurant? The patrons of the restaurant reported they were able to taste the difference between various brands of bottled water when actually they were all being filled in the yard behind the restaurant by a bloke with a hosepipe.

Did the water taste different? I don't know. The water stays the same, it is the emotional response that is altered.

You're missing the point. Yes there's a subjective aspect but there's also many definable qunatifiable objective asspactes. Levels of inflamation, blood pressure, resting heart rate. Dopamine responses hystamine responses.

Like it or not mere suggestion does have the power to manifest a definite objective, empirical and quantifiable physiological reposnse.

Don't just take my word for it. Do the reasearch (pub med, google scholar) and you'll find I'm telling the truth.

Or don't do the research, ignore the evidence and carrying on tlaking about subjective experiences of pain at the risk of being condemmed as a crotcheteer.

[Mike Hall]

You're missing the point. Yes there's a subjective aspect but there's also many definable qunatifiable objective asspactes. Levels of inflamation, blood pressure, resting heart rate. Dopamine responses hystamine responses.

Like it or not mere suggestion does have the power to manifest a definite objective, empirical and quantifiable physiological reposnse.

That's interesting.

All the material I'm familiar with discussing placebo suggests there has never been a good study which demonstrates any objective effect from placebo. The only studies where a positive effect is shown from placebo is on subjective measures.

I'll take a look through pubmed for studies testing placebo effects on the things you mention, cheers.

[Mike Hall]

Further to the above, the New England Journal of Medicine published "Is the Placebo Powerless?" in 2001, a meta-analysis of studies comparing placebo to no treatment.

The conclusion featured in the abstract states:


We found little evidence in general that placebos had powerful clinical effects. Although placebos had no significant effects on objective or binary outcomes, they had possible small benefits in studies with continuous subjective outcomes and for the treatment of pain. Outside the setting of clinical trials, there is no justification for the use of placebos.

(full study: http://content.nejm.org/cgi/content/abstract/344/21/1594)

Which sounds pretty damning to me. But as I say, I'll check up on PubMed for studies supporting placebo effects for objective outcomes. The study was in 2001, it could have been superceded by new research.

[Pebble]

Mike,

Here is a reasonable starting point:

Neuron. (javascript:AL_get(this,%20'jour',%20'Neuron.');) 2008 Jul 31;59(2):195-206.http://www.ncbi.nlm.nih.gov/corehtml/query/egifs/http:--linkinghub.elsevier.com-ihub-images-cellhub.gif (http://www.ukskeptics.com/entrez/utils/fref.fcgi?PrId=3048&itool=AbstractPlus-def&uid=18667148&db=pubmed&url=http://linkinghub.elsevier.com/retrieve/pii/S0896-6273%2808%2900585-0) Links (javascript:PopUpMenu2_Set(Menu18667148);)
New insights into the placebo and nocebo responses.

Enck P (http://www.ukskeptics.com/sites/entrez?Db=pubmed&Cmd=Search&Term=%22Enck%20P%22%5BAuthor%5D&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsP anel.Pubmed_DiscoveryPanel.Pubmed_RVAbstractPlus), Benedetti F (http://www.ukskeptics.com/sites/entrez?Db=pubmed&Cmd=Search&Term=%22Benedetti%20F%22%5BAuthor%5D&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsP anel.Pubmed_DiscoveryPanel.Pubmed_RVAbstractPlus), Schedlowski M (http://www.ukskeptics.com/sites/entrez?Db=pubmed&Cmd=Search&Term=%22Schedlowski%20M%22%5BAuthor%5D&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsP anel.Pubmed_DiscoveryPanel.Pubmed_RVAbstractPlus).
Department of Internal Medicine VI: Psychosomatic Medicine and Psychotherapy, University Hospital, 72076 Tübingen, Germany. paul.enck@uni-tuebingen.de
In modern medicine, the placebo response or placebo effect has often been regarded as a nuisance in basic research and particularly in clinical research. The latest scientific evidence has demonstrated, however, that the placebo effect and the nocebo effect, the negative effects of placebo, stem from highly active processes in the brain that are mediated by psychological mechanisms such as expectation and conditioning. These processes have been described in some detail for many diseases and treatments, and we now know that they can represent both strength and vulnerability in the course of a disease as well as in the response to a therapy. However, recent research and current knowledge raise several issues that we shall address in this review. We will discuss current neurobiological models like expectation-induced activation of the brain reward circuitry, Pavlovian conditioning, and anxiety mechanisms of the nocebo response. We will further explore the nature of the placebo responses in clinical trials and address major questions for future research such as the relationship between expectations and conditioning in placebo effects, the existence of a consistent brain network for all placebo effects, the role of gender in placebo effects, and the impact of getting drug-like effects without drugs.

[Mike Hall]

Cheers Pebble!

[Mike Hall]

I'm unable to find the full text of that study available for free anywhere - but reading the abstract, I'm not sure it conflicts with my position?


The latest scientific evidence has demonstrated, however, that the placebo effect and the nocebo effect, the negative effects of placebo, stem from highly active processes in the brain that are mediated by psychological mechanisms such as expectation and conditioning.

This appears to suggest that the placebo effect is psychological. Isn't that what I've been claiming?

(Edited to add: "claim" is probably too strong a word. My position is best summed up as, I have yet to be convinced there is a placebo effect beyond patient perception. Although the search, as ever, goes on :))

[Matt]

I'm unable to find the full text of that study available for free anywhere - but reading the abstract, I'm not sure it conflicts with my position?



This appears to suggest that the placebo effect is psychological. Isn't that what I've been claiming?

(Edited to add: "claim" is probably too strong a word. My position is best summed up as, I have yet to be convinced there is a placebo effect beyond patient perception. Although the search, as ever, goes on :))

OK here's evidence that the placebo effect (sham reiki in this case) affected measureable metrics


Results of the research showed that subjects in both the reiki and placebo groups experienced a significant reduction in heart rate, increase in cardiac vagal tone, increase in cardiac sensitivity to baroreflex, and reduction in respiratory rate.

http://www.massagemag.com/Magazine/2005/issue116/research116.4.php

Earlier I mentioned evidence that opiod antagonists affect the analgesic placebo response.

http://www.jneurosci.org/cgi/content/full/19/1/484?ijkey=28133dbf026656d9f9617ef7af23115ff298de90

The conclusion drawn is that some placebo effects actually cause the body to release endogenous opiods whilst other forms of the placebo effect may be merely subjective.


The neurobiology of placebo was born when Levine et al. (1978)http://www.jneurosci.org/icons/ref-arrow.gif (http://www.jneurosci.org/cgi/content/full/19/1/484?ijkey=28133dbf026656d9f9617ef7af23115ff298de90 #B23) discovered that the opioid antagonist naloxone inhibits the placebo analgesic response. There are now several lines of evidence indicating that placebos activate endogenous opioid systems, thus producing placebo analgesia

This study shows that different type of placebo have different physiological effects.

Telling someone you're about to give them a painkiller makes the body relase it's own opiod pain killers even if you only give them a placebo.
Giving someone opiods and then switching to a placebo also allows the body to produce it's own opiates where as giving them anti inflamtories and switching to a placebo produces a different type of placebo effect that doesn't seem to rely on the body producing it's own opiods.

Then there's the well know relationship between the neuroendocrine system and the immune system. Stress hormone are known to affect health in many way including supressing the immune system. A feeling of wellbeing may well help protect against the common cold (though this doesn't extend to cover all disease - you can't smile away cancer) It even has outcomes affecting the long term outcomes for heart disease patients. Cortisol is a stress hormone which harms the arterial system, placebos and nocebos can effect cortisol.

http://www.psychosomaticmedicine.org/cgi/content/full/65/5/786

Now of course the placebo effect is psychological in origin. That's no in question it's part of the definition. What pertinant to this discussion is that a psychological origin doesn't limit it to purely psychological effects but real objective measurable physiological effects.

It's not just that the doctors in the double blind trial had an expectation of reduced pain and recorded that due to bias, it's not that the patient has the expectation of reduced pain and so reported that due to bias. It's no even that pain is subjective so the patient experienced less pain due to expectations. In some case a physiological effect is observed whihc is know to lead to reduced pain.

FACT

We're only scratching the surface in the mechanisms behind these physiological effects but we know enough to be certain that in some cases they're very real.

[Mulder]

[quote=Matt;43337] ...sham reiki ...[quote]

Sorry, just thought the idea of sham reiki was funny. Do carry on ...

[Mike Hall]

I can't say I'm convinced by the Reiki data, not least because it was published in the Journal of Alternative and Complementary Medicine; hardly a reputable source. Briefly looking through their data on PubMed, they've also published studies concluding acupuncture is effective for treating Parkinsons and homeopathy is effective in treating a "variety" of chronic conditions.

It's hard to take any publication seriously which trumpts itself as "the official journal of the Society for Acupuncture Research"! :smiley:

Regarding the opiod blockers effecting placebo response, it's clear from the text of the study that the patients were primed to respond "means of cognitive expectation cues, drug conditioning, or a combination of both." Personally I'd call that a pavlovian response, not a placebo effect. What use it placebo if you have to prime the patient's body in how it's supposed to respond first?

But if you want to lump pavlovian conditioning in and say it is part of the placebo effect, (which is a perfectly reasonable thing to do, don't get me wrong) then I'll cheerily concede that placebos are effective in that context.

Myself, I'm more inclined to split rather than lump. And let pavlovian effects be pavlovian effects and placebo be placebo. I'd sooner avoid the type of equivocation problems you could otherwise encounter, as happens with acupuncture proponents claiming electroacupuncture as part of their woo - when its actually not.

Acupuncture, to my mind, is the ancient chinese art of redirecting the flow of chi around the body by inserting needles into specified meridians. That so-called electroacupuncture can be shown to have some theraputic benefits (which I understand is the case, though I'm not 100% on that) does not do anything to support it's parent Acupuncture (The Ancient Chinese Art Of).

But I digress. :smiley:

In the cortisol and beta-endorphin study, it seems fairly conclusive that both placebo and nocebo can produce a change in the body's stress levels. I'd be inclined to think this was also classical conditioning - although in this case the patients have been "primed" by society rather than specifically primed by the test administrators.

I'd be interested to know how a patient would respond if they did not know how they were supposed to react? I'd also have been inclined to add a further group to the study (placebo/no information) to control for the effect of the saline injection itself.

Again, if you want to consider learned responses as part of the placebo effect, then I think we're in agreement.

Interestingly, however, there are studies on PubMed suggesting that a placebo response can be elicited from animals -- which is an argument in favour of placebo that I would find very compelling. I'll have to read into that further when I get the time.

[Mike Hall]

Sorry, just thought the idea of sham reiki was funny. Do carry on ...

Oh yes. Rather like sham pixies and real pixies.... :smiley:

[Pebble]

OK, presumably you have access to BMJ, nice observations on irritable bowel syndrome - again of course this is probably purely a psycological effect on gut motility:

http://www.bmj.com/cgi/content/abstract/336/7651/999?ijkey=6942aa2b393a1ec67985989a59c4e09c0dbb8553&keytype2=tf_ipsecsha

However this effect on postprandial glucose is probably beyond what we would normally anticipate:

http://ejscontent.ebsco.com/ContentServer.aspx?target=http%3A%2F%2Fwww3.inters cience.wiley.com%2Fresolve%2Fdoi%2Fpdf%3FDOI%3D10. 1111%2Fj.1365-2125.2007.02929.x

Haven't seen that repeated to ensure not a one off observation.

[Tony Williams]

An interesting article on the placebo effect in the current New Scientist magazine (it's featured in the editorial as well).

While it seems clear from large-scale surveys that it has no effect on the progress of disease, it does have some effect in reducing the pain experienced by sufferers, sometimes in rather complex ways. The editorial sums it up as follows:


"It turns out that a patient's state of mind, awareness of their condition and expectations of the care they are about to receive can influence pretty much every facet of medicine, from consultations with a doctor to clinical trials of a new drug. For example, one set of researchers has found that the anxiety-relieving drug diazepam doesn't work unless patients know that they are taking it. Similarly, morphine is significantly more effective when people are told they are being given it. In both cases, the placebo effect is critical to the drug's effectiveness."

[Pebble]

"It turns out that a patient's state of mind, awareness of their condition and expectations of the care they are about to receive can influence pretty much every facet of medicine, from consultations with a doctor to clinical trials of a new drug. For example, one set of researchers has found that the anxiety-relieving drug diazepam doesn't work unless patients know that they are taking it. Similarly, morphine is significantly more effective when people are told they are being given it. In both cases, the placebo effect is critical to the drug's effectiveness."


Not wishing entirely to rain on the parade, 20mg of diazepam IV will relieve anxiety in almost anyone, without any need for the recipient or administrator being aware of what is happening, though a somewhat dangerous approach. But I agree with the gist.

[Ryoden]

Hi all,

I remember seeing a series of 4 programmes on the BBC, a female scientist (cant remember her name) was investigating acupuncture, faith healing, herbs and one other alternative remedy which I dont remember.

Apparently they ran a trial with 100 patients all who had a real knee condition that required an operation (it wasnt broken knee or anything but involved long term pain).

Half of them actually had the op while the other half went through everything except the op - ie they went into theatre were anaethetised, cut, stitched but no actual op.

Afterwards I think about 75% of the group who didnt have the actual op received varying reduction in pain, some of them over the long term.

It really surprised me at the time, if I remember correctly they put someone with a serious condition like parkinsons in an MRI scanner and gave them their medicine and watched the medicine cause an effect in the brain, then they gave a placebo and the brain was seen to produce the effect again.

The programme was a year or two ago and if anyone can remember seeing it I would like to know as its annoying the hell out of me that i cant remember.

Basically though it seemed to show that placebos can have an effect.

[Trinoc]

The programme was a year or two ago and if anyone can remember seeing it I would like to know as its annoying the hell out of me that i cant remember.
Is this (http://www.amazon.co.uk/Alternative-Medicine-Evidence-Complete-BBC/dp/B000JLTEFC/ref=sr_1_1?ie=UTF8&s=dvd&qid=1224276211&sr=8-1) what you're looking for?

[Ryoden]

Yes thanks that looks like the one.:smiley: